Field of the Invention
The present invention relates to a touch screen-integrated display device. More particularly, the present invention relates to a touch screen-integrated display device in which a flexible printed circuit board is connected with an entirety of a first pad connected with a display device and a second pad connected with a touch sensing device.
Description of the Related Art
A touch screen panel is a device configured to sense a user's touch input such as a screen touch or gesture with respect to a display device. The touch screen has been widely used for portable display devices such as a smart phone, and a tablet PC and large-sized display devices such as display devices in public facilities and smart TVs.
In a general display device, a touch screen panel is attached to an upper substrate. Usually, the touch screen panel is separately manufactured and attached to an external surface of the display device. Thus, a total thickness of the display device is undesirably large.
In recent years, in order to solve such problem, a so-called in-cell type touch screen-integrated display device that is manufactured by integrating a touch screen panel into a display panel has been developed.
FIG. 1A is a schematic perspective view provided to describe a touch screen-integrated display device of the related art. FIG. 1B is a schematic cross-sectional view provided to describe the touch screen-integrated display device taken along a line Ib-Ib′ of FIG. 1A. FIG. 1C is a schematic cross-sectional view provided to describe the touch screen-integrated display device taken along a line Ic-Ic′ of FIG. 1A.
Referring to FIG. 1A to FIG. 1C, the touch screen-integrated display device 100 may include a lower substrate 110, a first pad 111, a second pad 112, an upper substrate 120, a display element 130, a touch sensing element 140, a bonding layer 150, a driver integrated circuit 160, a first flexible printed circuit board 170, and a second flexible printed circuit board 190.
In an area of the lower substrate 110 which is not covered by the upper substrate 120 but exposed, a first pad area PA1 and a second pad area PA2 are disposed. In the first pad area PA1, the first pad 111 that provides electrical connection with the display element 130 is disposed, whereas in the second pad area PA2, the second pad 112 that provides electrical connection with the touch sensing element 140 is disposed.
An external printed circuit board, in which a timing controller, a touch integrated circuit, or the like are disposed, can be connected to the first pad 111 and the second pad 112 via the first flexible printed circuit board 170 and the second flexible printed circuit board 190. Namely, in order to connect the external printed circuit board with the first pad 111, the first flexible printed circuit board 170 is used. Also, in order to connect the external printed circuit board with the second pad 112, the second flexible printed circuit board 190 is used. In order to connect the external printed circuit board with the first flexible printed circuit board 170 and the second flexible printed circuit board 190, respective connectors 175 and 195 are used.
If a touch screen panel and a display panel are separate and non-integrated, separate flexible printed circuit boards that are connected with the touch screen panel and the display panel are needed to connect with each of the touch screen panel and the display panel with an external printed circuit board.